As techniques of observing a magnetization state of a magnetic specimen by means of an electron microscope, a method for detection of Lorentz deflection of an electron beam transmitting through the specimen (Lorentz electron microscope) or a method for detection of spin polarization of secondary electrons (spin polarization SEM) has been used. Of them, the Lorentz electron microscope is described in, for example, Surface Science, Vol. 13, pp. 525-532 (1992) and the spin polarization SEM is also described in Surface Science, Vol. 13, pp. 512-527 (1992).